Ventilators are used by people of all ages, from premature infants to adults, who have any number of health problems that for one reason or another impair their ability to breathe normally.

Ventilators perform one of the most complex functions of the body  ventilation, a process in which the lungs take in and disperse oxygen the body needs and gather up and expel the carbon dioxide created as a result of body functions. In healthy people, this gas exchange takes place in the small air sacs of the lungs, called alveoli and, in the course of one day, normally involves 8,000 to 9,000 liters of blood pumped through the lungs by the heart.